Economizer based ambient cooling of data centers has been proposed as a technique to reduce data center power consumption. Economizer based ambient cooling of data centers is typically limited to winter months and requires refrigeration based cooling during hot temperature months. In any locale where temperatures below freezing are anticipated, an antifreeze solution (typically glycol based) is required within the coolant loop that is exposed to the ambient environment to avoid freeze-up if the loop circulation stops for any reason. This antifreeze solution is not as effective in thermal transport as water alone, with the degree of ineffectiveness varying depending on the exact character of the devices putting heat into the coolant loop. This lower efficiency can be significant when attempting to allow for ambient air cooling at high ambient temperatures.